What is the 17 day diet?

Days 1 - 17 are to "Accelerate" on a low carbohydrate diet that provides around 1200 calories.

Days 18 - 34 are to "Activate" by calorie cycling (aka calorie shifting or calorie zigzagging), which means that the daily calorie intake cycles and recycles from low to high over the course of several days.

Days 35 - 51 are to "Achieve" good eating habits that last a lifetime.

Day 52 and on are to "Arrive" at a lifelong eating plan, which is a constant cycling through phases 1, 2 and 3 - until the weekends when you can splurge.